Fluid circuit interrupter



D. ULREY ET AL FLUID CIRCUIT INTERRUPTER Oct. 14 1924.

Filed July 13 1922 Fig.1.

l'h M l 1 lur l INVENTORS Dayfon Ulrey Dang I. Mayne ATTORNEY Patented Oct. 14, 1924.

UNITED STATES 1,511,382 PATENT OFFICE.

DAYTON ULREY AND DANIEL I. MAYNE, OF WILKINSBURG, PENNSYLVANIA, AS- SIGNORS TO WESTINGHOUSE ELECTRIC AND MANUFACTURING COMPANY, A COR- PORATION OF PENNSYLVANIA.

FLUID CIRCUIT INTEIRRUPTER.

Application filed July 13, 1922. Serial No. 574,619.

To all whomc't may concern:

Be it known that we, DAYTON ULREY, a citizen of the United States, and a. resident of Wilkinsburg, in the county of Allegheny and State of Pennsylvania, and DANIEL I. MAYNE, a citizen of the United States, and a resident of Wilkinsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvementin Fluid Circuit Interrupters, of which the following is a specification.

Our invention relates to. circuit interrupters and particularly to fluid circuit interrupters and it has for one of its objects to provide a relatively simple, compact and rugged construction of fluid circuit interrupter that shall be efiective to interrupt an electric circuit by either manual or automatic operation.

Another object of our invention is to provide a fluid circuit interrupter that shall be effective to interrupt the circuit between portions of the column of conducting fluid and that shall embody means to cause the interruption to occur at a predetermined point in the device.

In practising our invention, we provide a closed evacuated tube of insulating material within which is placed a quantity of conducting fluid having a relativel high surface tension, such as mercury. T e tube may be of substantially U-shape, the end of one portion being of substantially spherical contour and a constricted portion being provided immediately adjacent the spherical end. The end of the other'portion is of slightly. larger diameter in cross-section than the main portion and constitutes a receiving chamber for the conducting fluid when the device operates to interrupt the circuit. A pair of electric circuit terminals extend into the tube in suitable spaced-apart relation.

This application is a continuation, in part, and an improvement on, the device described and claimed in copending application Serial No. 503,796, filed by O. A. Colby, September 28, 1921, and assigned to the Westinghouse Electric & Manufacturing Company.

In the single sheet of drawings,

Figure 1 is a view, in side elevation, of an electrically heated device with which is associated the device embodying our invention, certain parts being cut away;

Fig. 2 is a view, in vertical section, of a device embodying our invention;

7 Fig. 3 is a view, in rear elevation, of the device illustrated in Fig. 2;

Fig. 4. is a View, in Vertical section, of a modification. of the device embodying our invention;

Fig. 5 is a View, in rear elevation, of the modification illustrated in Fig. 4, a port-ion being shown in section, and

Fig. 6 is a view, in vertical lateral section, of a still further modification of the device embodying our invention.

An electric iron, designated generally by the numeral 11, comprises a sole plate 12, an electric heating element 13, a top plate 14 and a cover member 15. The heating element and the top plate may be suitably secured against the sole plate by means of a plurality of bolts 16, only one of which is shown in the drawing. The cover member may be held in proper operative position'by a s1ngle bolt 17 extending into the top plate. A handle member 18 is supported at the upper end of two handle strap members 19 and 21, the lower ends of which are secured against the cover member by rivets 22.

While we have chosen to illustrate the device embodying our invention, to be hereinafter described more in detail, as operatively associated with an electric iron, it is to be understood that the electric iron is representative of the type of electrically heated apparatus with which the device embod ing our invention may be employed and t e construction. illustrated is, therefore, to be taken as representative only, as the different details thereof do not constitute a part of our invention. The terminals of the resistor of the electric heating element 13 may be suitably connected to upwardly extending terminal straps 23, which may be held in proper operative position by a metallic terminal-strap-supporting member 24, of substantially U-shape, one end of which is held by one of the bolts 16. A plurality of small bolts 25 may be employed to secure the terminals of the resistor against the terminal straps 23 and the terminal straps against the supporting member 24, suitable insulating washers 26 being employed to electrically insulate the terminal straps from the sup porting member 24.

other suitable or desired manner.

A. terminal casing 27 is located at the rear end of the iron and suitably secured either against the rear handle strap 21 or in any A suitable supply-circuit conductor 28 is provided having one end extending into the terminal casing 27, a helical spring 29 being provided immediately outside of the terminal casing to prevent undue kinking of the conductors 28..

A fluid circuit interrupter 31 is mounted in the casing 27. The interrupter 31 comprises a closed evacuated tube 32 of insulatin material, such as glass or quartz, and of substantially U-shape, one leg thereof being shorter than the other leg. The end of the longer leg of the tube 32 is of substantially spherical shape and a contracted portion 33 of the tube is provided immediately adjacent thereto. We have found that very good results are obtained if the internal diameter of the outer end portion is made approximately one-fourth of an inch, the in ternal diameter of the constricted portion 32 is made about one-eighth of an inch in diameter, the main portion of the tube is made three-sixteenths of an inch in internal diameter, and the internal diameter of the other portion 34 is made one-fourth of an inch in diameter. A pair of electric circuit terminals 35 and 36 extend into the tube 32, the terminal 35 extending into the tube adjacent the middle portion thereof and ex tending substantially longitudinally of the main portion thereof while the terminal 36 extends into the tube at the spherical end portion hereinbefore described. A quantity of a conducting fluid 37 is placed within the tube 32, the amount being such that, when the tube is held in its proper operative position with the intermediate portion uppermost, the conducting fluid fills substan' tially all of the longer portion of the tube. We prefer to employ a conducting fluid having a relatively high surface tension, such as mercury. I

Figs. 4 and 5 illustrate a modification of the device embodying our invention, the difference being mainly that a lateral tubular extension 38 is provided adjacent the intermediate portion of the tube, into which the electric circuit terminal 35 extends. A con stricted portion 39 connects the auxiliary portion 38 with the main portion of the tube in order to insure that the electric circuit terminal 35 shall always have operatively associated therewith a quantity of conductin fluid.

ig. 6 illustrates a still further modification of the device embodying our invention, the difl'erence comprising the location of an auxiliary tube portion 41, which is here shown as lying in the same plane as the two portions of the tube, the short portion 34 enteng at substantially right angles to the main portion of the tube and not parallel thereto, as in the device illustrated in Figs. 2, 3, 4 and 5 of the drawing.

The operation of the device is substantially as follows, it being assumed that the device is mounted substantially as illustrated in Fig. l of the drawing so that it will be resiliently supported by the electric circuit terminal wires 35 and 36, while, at the same time, being electrically connected in circuit thereby. As the electric iron heats up it will communicate a part of its'heat to the spherical end portion ofthe tube by direct radiation. A certain amount of heat will also be carried to the conducting fluid located in the spherical end portion by the electric circuit terminal wire 36 and convection currents of heated air also tend to conduct heat thereto. When the temperature of the electrically heated device becomes sufficiently high and has been maintained for a suficient length of time, a portion of the conducting fluid located in or immediatel above the constricted portion becomes volatilized. When a suflicient amount has become volatilized to separate the column of fluid, an arc occurs in the vapor, resulting in sufficiently rapid vaporization of the fluid to throw a portion of the conducting fluid over into the receiving portion 34 of the tube. The function of the constricted portion 33 is to cause this explosive action to occur at the constricted portion, as the weight of the conducting fluid is less at that point than it is at the bottom of the spherical end portion of the tube, and the cohesion of the conducting fluid is less because of the lesser area. The shape normally assumed by a mass of mercury free to do so is substantially that of a sphere, because of its relatively high surface tension and this cooperates with the substantiall spherical end portion in which it is co 'ned in causing the mercury to remain in the end portion, the break occurring at or above the constricted portion. We have found that with the tube constructed substantially as hereinbefore described the mercury moves as a column rather than flowing as a stream above the constricted portion when the device is employed as a manually operated circuit interrupter, thus insuring quick and positive interruption of the circuit.

When it is desired to reclose the circuit, after either a manual or an automatic operation of the device, the iron may be tilted backwardly and the mercury will easily and quickly flow into the main portion of the tube from the expanded portion 34, causing quick reclosing of the circuit.

The device embodying our invention thus provides a relatively simple and compact fluid circuit interrupter which may be operated either manually or automatically, and which is eflective to cause the interruption to occur at a predetermined portion of the length of the column of conducting fluid, thereby avoiding any deleterious effects of an oxidized terminal wire, which insures that the device will 0 rate a relatively large number of times wit ou-t deterioration.

Various modifications may be made in the device embodying our invention without departing from the spirit and scope thereof and we desire that only such limitations shall be placed thereon as are imposed by the prior art or are specifically set forth in the-appended claims.

We claim as our invention:

1. In an electrically heated device, in combination, a heating means and means for controlling the circuit of said heating means, said controlling means comprising a closed elongated evacuated tube, a colunm of conducting fluid therein, a plurality of contact terminals normally operatively engaging said fluid column, only one end of said tube and fluid column being in heatreceiving relation to said heating means whereby a portion of said fluid column adj acent said end is volatilized upon the occur rence of a predetermined temperature in said heating element, and embodying means in said tube adjacent said end for causing said volatilized fluid to break said fluid column intermediate its ends at a predetermined point.

2. In an electrically heated device, in combination, a heating element and a circuit-controlling means comprising a closed evacuated elongated tube of insulating material having a spherical end portion, a relatively short constricted portion adjacent to said spherical end portion, an intermediate portion and an enlarged end portion, a normally continuous column of conducting fluid located in said spherical, constricted and intermediate portions of said tube, and a plurality of supply-circuit leads extending through the wall of said tube and operatively engaging said fluid column adjacent its ends, the spherical end of said tube only being under the direct thermal influence of said heating element.

3. In an electrically heated device, in combination, a heating element and a circuit-controlling means comprising a closed evacuated elongated tube of insulating material having a spherical end portion, a relatively short constricted portion adjacent to said spherical end portion, an intermediate portion and an enlarged end portion, a normally continuous column of conducting fluid having a relatively high surface tension, located in said spherical, constricted and intermediate portions of said tube, and a plurality of supply circuit leads extending through the wall of said tube and operatively engaging said fluid column adjacent its ends, the spherical end of said tube only being under the direct thermal influence of said heating element, whereby a portion ofthe fluid in said spherical portion is volatilized upon the occurrence of a predetermined temperature and operates to cause said column of fluid to break at the constricted portion of the tube to interrupt an electric circuit therethrough.

In testimony whereof, we have hereunto subscribed our names this 11th day of July, 1922.

DAYTON ULREY. DANIEL I. MAYNE. 

